ORIGINAL: mike_o
What I also found is that the 620 diff thrust bearing is dead. Anywhere to get that without buying an entire set of bearings?
I know it's a late reply but i had the same problem and i got a cuple of thrust bearings from [link=http://cgi.ebay.com.au/Tamiya-RC-Thrust-Ball-Bearings-2x6x3-R-C-Bearing-2x6-mm-/130257586088?pt=LH_DefaultDomain_0&hash=item1e53f507a8]HERE[/link]
The hardest part was to find replacements for the nut and bolt that holds the whole diff together
ORIGINAL: Krazy Chicken
how do you set a ball diff? do i tighten it as tight as i can, then back it off one complete turn?
The assembly instructions show how to assemble the diff and tension it. I tightened it until it was quite difficult to spin the diff cups in opposite directions using a couple of hex keys as handles